Quoting Tvrtko Ursulin (2018-01-17 12:27:50) > > On 17/01/2018 12:15, Chris Wilson wrote: > > When testing that the timeout fired, we need to be sure we have waited > > just long enough for the timeout to have occurred and for the softirq > > (on another cpu) to have completed. Sleeping for an arbitrary amount is > > prone to error, so wait for the timeout instead and complain if it was > > too late. > > > > References: https://bugs.freedesktop.org/show_bug.cgi?id=104670 > > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > > Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx> > > --- > > drivers/gpu/drm/i915/selftests/i915_sw_fence.c | 30 +++++++++----------------- > > 1 file changed, 10 insertions(+), 20 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/selftests/i915_sw_fence.c b/drivers/gpu/drm/i915/selftests/i915_sw_fence.c > > index 4fb51deb81a1..f171db16a1c4 100644 > > --- a/drivers/gpu/drm/i915/selftests/i915_sw_fence.c > > +++ b/drivers/gpu/drm/i915/selftests/i915_sw_fence.c > > @@ -661,7 +661,7 @@ static int test_dma_fence(void *arg) > > { > > struct i915_sw_fence *timeout = NULL, *not = NULL; > > unsigned long delay = i915_selftest.timeout_jiffies; > > - unsigned long end, sleep; > > + unsigned long start, end; > > struct dma_fence *dma; > > int err; > > > > @@ -688,36 +688,26 @@ static int test_dma_fence(void *arg) > > } > > > > /* We round the timeout for the fence up to the next second */ > > - end = round_jiffies_up(jiffies + delay); > > + start = jiffies; > > + end = round_jiffies_up(start + delay); > > > > - sleep = jiffies_to_usecs(delay) / 3; > > - usleep_range(sleep, 2 * sleep); > > - if (time_after(jiffies, end)) { > > - pr_debug("Slept too long, delay=%lu, skipping!\n", delay); > > - goto skip; > > + if (wait_event_interruptible(timeout->wait, > > + i915_sw_fence_done(timeout))) { > > + err = -EINTR; > > + goto err; > > But can now hang forever if broken. Which is why I allowed it to be interrupted. Maybe wait_event_killable()? > How about short sleeps in a loop until a timeout? I kind of like the idea of using the waitqueue now :) How about if I attach a timer to kick the waitqueue instead. -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
